LightPC: hardware and software co-design for energy-efficient full system persistence

We propose LightPC, a lightweight persistence-centric platform to make the system robust against power loss. LightPC consists of hardware and software subsystems, each being referred to as open-channel PMEM ( OC-PMEM ) and persistence-centric OS ( PecOS ). OC-PMEM removes physical and logical boundaries in drawing a line between volatile and nonvolatile data structures by unshackling new memory media from conventional PMEM complex. PecOS provides a single execution persistence cut to quickly convert the execution states to persistent information in cases of a power failure, which can eliminate persistent control overhead. We prototype LightPC's computing complex and OC-PMEM using our custom system board. PecOS is implemented based on Linux 4.19 and Berkeley bootloader on the hardware prototype. Our evaluation results show that OC-PMEM can make user-level performance comparable with a DRAM-only non-persistent system, while consuming 73% lower power and 69% less energy. LightPC also shortens the execution time of diverse HPC, SPEC, and In-memory DB workloads, compared to traditional persistent systems by 4.3X, on average.